Michigan Democrat Mallory McMorrow ends bid for US Senate

Exit leaves primary voters to choose between progressive Abdul El-Sayed and centrist Haley Stevens in must-win seat

Mallory McMorrow, a Michigan Democrat, has dropped out of a contentious US Senate primary campaign, setting up a straight fight between the party's progressive and establishment wings - represented by Abdul El-Sayed, a former public health official, and Haley Stevens, a congresswoman.

McMorrow's retreat marks the end of a center-left bid to hold the seat being vacated this year by the Democrat Gary Peters. The three-way primary contest was a close one earlier in the campaign, but polls indicated that McMorrow's support had plunged in recent weeks, as El-Sayed raced past her and Stevens to emerge as the frontrunner for the party's nomination.